1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MM_TYPES_H
3 #define _LINUX_MM_TYPES_H
5 #include <linux/mm_types_task.h>
7 #include <linux/auxvec.h>
8 #include <linux/list.h>
9 #include <linux/spinlock.h>
10 #include <linux/rbtree.h>
11 #include <linux/rwsem.h>
12 #include <linux/completion.h>
13 #include <linux/cpumask.h>
14 #include <linux/uprobes.h>
15 #include <linux/page-flags-layout.h>
16 #include <linux/workqueue.h>
17 #include <linux/seqlock.h>
21 #ifndef AT_VECTOR_SIZE_ARCH
22 #define AT_VECTOR_SIZE_ARCH 0
24 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
32 * Each physical page in the system has a struct page associated with
33 * it to keep track of whatever it is we are using the page for at the
34 * moment. Note that we have no way to track which tasks are using
35 * a page, though if it is a pagecache page, rmap structures can tell us
38 * If you allocate the page using alloc_pages(), you can use some of the
39 * space in struct page for your own purposes. The five words in the main
40 * union are available, except for bit 0 of the first word which must be
41 * kept clear. Many users use this word to store a pointer to an object
42 * which is guaranteed to be aligned. If you use the same storage as
43 * page->mapping, you must restore it to NULL before freeing the page.
45 * If your page will not be mapped to userspace, you can also use the four
46 * bytes in the mapcount union, but you must call page_mapcount_reset()
49 * If you want to use the refcount field, it must be used in such a way
50 * that other CPUs temporarily incrementing and then decrementing the
51 * refcount does not cause problems. On receiving the page from
52 * alloc_pages(), the refcount will be positive.
54 * If you allocate pages of order > 0, you can use some of the fields
55 * in each subpage, but you may need to restore some of their values
58 * SLUB uses cmpxchg_double() to atomically update its freelist and
59 * counters. That requires that freelist & counters be adjacent and
60 * double-word aligned. We align all struct pages to double-word
61 * boundaries, and ensure that 'freelist' is aligned within the
64 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
65 #define _struct_page_alignment __aligned(2 * sizeof(unsigned long))
67 #define _struct_page_alignment
71 unsigned long flags
; /* Atomic flags, some possibly
72 * updated asynchronously */
74 * Five words (20/40 bytes) are available in this union.
75 * WARNING: bit 0 of the first word is used for PageTail(). That
76 * means the other users of this union MUST NOT use the bit to
77 * avoid collision and false-positive PageTail().
80 struct { /* Page cache and anonymous pages */
82 * @lru: Pageout list, eg. active_list protected by
83 * lruvec->lru_lock. Sometimes used as a generic list
87 /* See page-flags.h for PAGE_MAPPING_FLAGS */
88 struct address_space
*mapping
;
89 pgoff_t index
; /* Our offset within mapping. */
91 * @private: Mapping-private opaque data.
92 * Usually used for buffer_heads if PagePrivate.
93 * Used for swp_entry_t if PageSwapCache.
94 * Indicates order in the buddy system if PageBuddy.
96 unsigned long private;
98 struct { /* page_pool used by netstack */
100 * @pp_magic: magic value to avoid recycling non
101 * page_pool allocated pages.
103 unsigned long pp_magic
;
104 struct page_pool
*pp
;
105 unsigned long _pp_mapping_pad
;
106 unsigned long dma_addr
;
109 * dma_addr_upper: might require a 64-bit
110 * value on 32-bit architectures.
112 unsigned long dma_addr_upper
;
114 * For frag page support, not supported in
115 * 32-bit architectures with 64-bit DMA.
117 atomic_long_t pp_frag_count
;
120 struct { /* slab, slob and slub */
122 struct list_head slab_list
;
123 struct { /* Partial pages */
126 int pages
; /* Nr of pages left */
127 int pobjects
; /* Approximate count */
134 struct kmem_cache
*slab_cache
; /* not slob */
135 /* Double-word boundary */
136 void *freelist
; /* first free object */
138 void *s_mem
; /* slab: first object */
139 unsigned long counters
; /* SLUB */
147 struct { /* Tail pages of compound page */
148 unsigned long compound_head
; /* Bit zero is set */
150 /* First tail page only */
151 unsigned char compound_dtor
;
152 unsigned char compound_order
;
153 atomic_t compound_mapcount
;
154 unsigned int compound_nr
; /* 1 << compound_order */
156 struct { /* Second tail page of compound page */
157 unsigned long _compound_pad_1
; /* compound_head */
158 atomic_t hpage_pinned_refcount
;
159 /* For both global and memcg */
160 struct list_head deferred_list
;
162 struct { /* Page table pages */
163 unsigned long _pt_pad_1
; /* compound_head */
164 pgtable_t pmd_huge_pte
; /* protected by page->ptl */
165 unsigned long _pt_pad_2
; /* mapping */
167 struct mm_struct
*pt_mm
; /* x86 pgds only */
168 atomic_t pt_frag_refcount
; /* powerpc */
170 #if ALLOC_SPLIT_PTLOCKS
176 struct { /* ZONE_DEVICE pages */
177 /** @pgmap: Points to the hosting device page map. */
178 struct dev_pagemap
*pgmap
;
179 void *zone_device_data
;
181 * ZONE_DEVICE private pages are counted as being
182 * mapped so the next 3 words hold the mapping, index,
183 * and private fields from the source anonymous or
184 * page cache page while the page is migrated to device
186 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also
187 * use the mapping, index, and private fields when
188 * pmem backed DAX files are mapped.
192 /** @rcu_head: You can use this to free a page by RCU. */
193 struct rcu_head rcu_head
;
196 union { /* This union is 4 bytes in size. */
198 * If the page can be mapped to userspace, encodes the number
199 * of times this page is referenced by a page table.
204 * If the page is neither PageSlab nor mappable to userspace,
205 * the value stored here may help determine what this page
206 * is used for. See page-flags.h for a list of page types
207 * which are currently stored here.
209 unsigned int page_type
;
211 unsigned int active
; /* SLAB */
212 int units
; /* SLOB */
215 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */
219 unsigned long memcg_data
;
223 * On machines where all RAM is mapped into kernel address space,
224 * we can simply calculate the virtual address. On machines with
225 * highmem some memory is mapped into kernel virtual memory
226 * dynamically, so we need a place to store that address.
227 * Note that this field could be 16 bits on x86 ... ;)
229 * Architectures with slow multiplication can define
230 * WANT_PAGE_VIRTUAL in asm/page.h
232 #if defined(WANT_PAGE_VIRTUAL)
233 void *virtual; /* Kernel virtual address (NULL if
234 not kmapped, ie. highmem) */
235 #endif /* WANT_PAGE_VIRTUAL */
237 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
240 } _struct_page_alignment
;
242 static inline atomic_t
*compound_mapcount_ptr(struct page
*page
)
244 return &page
[1].compound_mapcount
;
247 static inline atomic_t
*compound_pincount_ptr(struct page
*page
)
249 return &page
[2].hpage_pinned_refcount
;
253 * Used for sizing the vmemmap region on some architectures
255 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page)))
257 #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK)
258 #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE)
260 #define page_private(page) ((page)->private)
262 static inline void set_page_private(struct page
*page
, unsigned long private)
264 page
->private = private;
267 struct page_frag_cache
{
269 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
275 /* we maintain a pagecount bias, so that we dont dirty cache line
276 * containing page->_refcount every time we allocate a fragment.
278 unsigned int pagecnt_bias
;
282 typedef unsigned long vm_flags_t
;
285 * A region containing a mapping of a non-memory backed file under NOMMU
286 * conditions. These are held in a global tree and are pinned by the VMAs that
290 struct rb_node vm_rb
; /* link in global region tree */
291 vm_flags_t vm_flags
; /* VMA vm_flags */
292 unsigned long vm_start
; /* start address of region */
293 unsigned long vm_end
; /* region initialised to here */
294 unsigned long vm_top
; /* region allocated to here */
295 unsigned long vm_pgoff
; /* the offset in vm_file corresponding to vm_start */
296 struct file
*vm_file
; /* the backing file or NULL */
297 struct file
*vm_prfile
; /* the virtual backing file or NULL */
299 int vm_usage
; /* region usage count (access under nommu_region_sem) */
300 bool vm_icache_flushed
: 1; /* true if the icache has been flushed for
304 #ifdef CONFIG_USERFAULTFD
305 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, })
306 struct vm_userfaultfd_ctx
{
307 struct userfaultfd_ctx
*ctx
;
309 #else /* CONFIG_USERFAULTFD */
310 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {})
311 struct vm_userfaultfd_ctx
{};
312 #endif /* CONFIG_USERFAULTFD */
315 * This struct describes a virtual memory area. There is one of these
316 * per VM-area/task. A VM area is any part of the process virtual memory
317 * space that has a special rule for the page-fault handlers (ie a shared
318 * library, the executable area etc).
320 struct vm_area_struct
{
321 /* The first cache line has the info for VMA tree walking. */
323 unsigned long vm_start
; /* Our start address within vm_mm. */
324 unsigned long vm_end
; /* The first byte after our end address
327 /* linked list of VM areas per task, sorted by address */
328 struct vm_area_struct
*vm_next
, *vm_prev
;
330 struct rb_node vm_rb
;
333 * Largest free memory gap in bytes to the left of this VMA.
334 * Either between this VMA and vma->vm_prev, or between one of the
335 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps
336 * get_unmapped_area find a free area of the right size.
338 unsigned long rb_subtree_gap
;
340 /* Second cache line starts here. */
342 struct mm_struct
*vm_mm
; /* The address space we belong to. */
345 * Access permissions of this VMA.
346 * See vmf_insert_mixed_prot() for discussion.
348 pgprot_t vm_page_prot
;
349 unsigned long vm_flags
; /* Flags, see mm.h. */
352 * For areas with an address space and backing store,
353 * linkage into the address_space->i_mmap interval tree.
357 unsigned long rb_subtree_last
;
361 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
362 * list, after a COW of one of the file pages. A MAP_SHARED vma
363 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
364 * or brk vma (with NULL file) can only be in an anon_vma list.
366 struct list_head anon_vma_chain
; /* Serialized by mmap_lock &
368 struct anon_vma
*anon_vma
; /* Serialized by page_table_lock */
370 /* Function pointers to deal with this struct. */
371 const struct vm_operations_struct
*vm_ops
;
373 /* Information about our backing store: */
374 unsigned long vm_pgoff
; /* Offset (within vm_file) in PAGE_SIZE
376 struct file
* vm_file
; /* File we map to (can be NULL). */
377 struct file
*vm_prfile
; /* shadow of vm_file */
378 void * vm_private_data
; /* was vm_pte (shared mem) */
381 atomic_long_t swap_readahead_info
;
384 struct vm_region
*vm_region
; /* NOMMU mapping region */
387 struct mempolicy
*vm_policy
; /* NUMA policy for the VMA */
389 struct vm_userfaultfd_ctx vm_userfaultfd_ctx
;
390 } __randomize_layout
;
393 struct task_struct
*task
;
394 struct core_thread
*next
;
399 struct core_thread dumper
;
400 struct completion startup
;
406 struct vm_area_struct
*mmap
; /* list of VMAs */
407 struct rb_root mm_rb
;
408 u64 vmacache_seqnum
; /* per-thread vmacache */
410 unsigned long (*get_unmapped_area
) (struct file
*filp
,
411 unsigned long addr
, unsigned long len
,
412 unsigned long pgoff
, unsigned long flags
);
414 unsigned long mmap_base
; /* base of mmap area */
415 unsigned long mmap_legacy_base
; /* base of mmap area in bottom-up allocations */
416 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
417 /* Base addresses for compatible mmap() */
418 unsigned long mmap_compat_base
;
419 unsigned long mmap_compat_legacy_base
;
421 unsigned long task_size
; /* size of task vm space */
422 unsigned long highest_vm_end
; /* highest vma end address */
425 #ifdef CONFIG_MEMBARRIER
427 * @membarrier_state: Flags controlling membarrier behavior.
429 * This field is close to @pgd to hopefully fit in the same
430 * cache-line, which needs to be touched by switch_mm().
432 atomic_t membarrier_state
;
436 * @mm_users: The number of users including userspace.
438 * Use mmget()/mmget_not_zero()/mmput() to modify. When this
439 * drops to 0 (i.e. when the task exits and there are no other
440 * temporary reference holders), we also release a reference on
441 * @mm_count (which may then free the &struct mm_struct if
442 * @mm_count also drops to 0).
447 * @mm_count: The number of references to &struct mm_struct
448 * (@mm_users count as 1).
450 * Use mmgrab()/mmdrop() to modify. When this drops to 0, the
451 * &struct mm_struct is freed.
456 atomic_long_t pgtables_bytes
; /* PTE page table pages */
458 int map_count
; /* number of VMAs */
460 spinlock_t page_table_lock
; /* Protects page tables and some
464 * With some kernel config, the current mmap_lock's offset
465 * inside 'mm_struct' is at 0x120, which is very optimal, as
466 * its two hot fields 'count' and 'owner' sit in 2 different
467 * cachelines, and when mmap_lock is highly contended, both
468 * of the 2 fields will be accessed frequently, current layout
469 * will help to reduce cache bouncing.
471 * So please be careful with adding new fields before
472 * mmap_lock, which can easily push the 2 fields into one
475 struct rw_semaphore mmap_lock
;
477 struct list_head mmlist
; /* List of maybe swapped mm's. These
478 * are globally strung together off
479 * init_mm.mmlist, and are protected
484 unsigned long hiwater_rss
; /* High-watermark of RSS usage */
485 unsigned long hiwater_vm
; /* High-water virtual memory usage */
487 unsigned long total_vm
; /* Total pages mapped */
488 unsigned long locked_vm
; /* Pages that have PG_mlocked set */
489 atomic64_t pinned_vm
; /* Refcount permanently increased */
490 unsigned long data_vm
; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */
491 unsigned long exec_vm
; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */
492 unsigned long stack_vm
; /* VM_STACK */
493 unsigned long def_flags
;
496 * @write_protect_seq: Locked when any thread is write
497 * protecting pages mapped by this mm to enforce a later COW,
498 * for instance during page table copying for fork().
500 seqcount_t write_protect_seq
;
502 spinlock_t arg_lock
; /* protect the below fields */
504 unsigned long start_code
, end_code
, start_data
, end_data
;
505 unsigned long start_brk
, brk
, start_stack
;
506 unsigned long arg_start
, arg_end
, env_start
, env_end
;
508 unsigned long saved_auxv
[AT_VECTOR_SIZE
]; /* for /proc/PID/auxv */
511 * Special counters, in some configurations protected by the
512 * page_table_lock, in other configurations by being atomic.
514 struct mm_rss_stat rss_stat
;
516 struct linux_binfmt
*binfmt
;
518 /* Architecture-specific MM context */
519 mm_context_t context
;
521 unsigned long flags
; /* Must use atomic bitops to access */
523 struct core_state
*core_state
; /* coredumping support */
526 spinlock_t ioctx_lock
;
527 struct kioctx_table __rcu
*ioctx_table
;
531 * "owner" points to a task that is regarded as the canonical
532 * user/owner of this mm. All of the following must be true in
533 * order for it to be changed:
535 * current == mm->owner
537 * new_owner->mm == mm
538 * new_owner->alloc_lock is held
540 struct task_struct __rcu
*owner
;
542 struct user_namespace
*user_ns
;
544 /* store ref to file /proc/<pid>/exe symlink points to */
545 struct file __rcu
*exe_file
;
546 #ifdef CONFIG_MMU_NOTIFIER
547 struct mmu_notifier_subscriptions
*notifier_subscriptions
;
549 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
550 pgtable_t pmd_huge_pte
; /* protected by page_table_lock */
552 #ifdef CONFIG_NUMA_BALANCING
554 * numa_next_scan is the next time that the PTEs will be marked
555 * pte_numa. NUMA hinting faults will gather statistics and
556 * migrate pages to new nodes if necessary.
558 unsigned long numa_next_scan
;
560 /* Restart point for scanning and setting pte_numa */
561 unsigned long numa_scan_offset
;
563 /* numa_scan_seq prevents two threads setting pte_numa */
567 * An operation with batched TLB flushing is going on. Anything
568 * that can move process memory needs to flush the TLB when
569 * moving a PROT_NONE or PROT_NUMA mapped page.
571 atomic_t tlb_flush_pending
;
572 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
573 /* See flush_tlb_batched_pending() */
574 bool tlb_flush_batched
;
576 struct uprobes_state uprobes_state
;
577 #ifdef CONFIG_HUGETLB_PAGE
578 atomic_long_t hugetlb_usage
;
580 struct work_struct async_put_work
;
582 #ifdef CONFIG_IOMMU_SUPPORT
585 } __randomize_layout
;
588 * The mm_cpumask needs to be at the end of mm_struct, because it
589 * is dynamically sized based on nr_cpu_ids.
591 unsigned long cpu_bitmap
[];
594 extern struct mm_struct init_mm
;
596 /* Pointer magic because the dynamic array size confuses some compilers. */
597 static inline void mm_init_cpumask(struct mm_struct
*mm
)
599 unsigned long cpu_bitmap
= (unsigned long)mm
;
601 cpu_bitmap
+= offsetof(struct mm_struct
, cpu_bitmap
);
602 cpumask_clear((struct cpumask
*)cpu_bitmap
);
605 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
606 static inline cpumask_t
*mm_cpumask(struct mm_struct
*mm
)
608 return (struct cpumask
*)&mm
->cpu_bitmap
;
612 extern void tlb_gather_mmu(struct mmu_gather
*tlb
, struct mm_struct
*mm
);
613 extern void tlb_gather_mmu_fullmm(struct mmu_gather
*tlb
, struct mm_struct
*mm
);
614 extern void tlb_finish_mmu(struct mmu_gather
*tlb
);
616 static inline void init_tlb_flush_pending(struct mm_struct
*mm
)
618 atomic_set(&mm
->tlb_flush_pending
, 0);
621 static inline void inc_tlb_flush_pending(struct mm_struct
*mm
)
623 atomic_inc(&mm
->tlb_flush_pending
);
625 * The only time this value is relevant is when there are indeed pages
626 * to flush. And we'll only flush pages after changing them, which
629 * So the ordering here is:
631 * atomic_inc(&mm->tlb_flush_pending);
638 * mm_tlb_flush_pending();
643 * atomic_dec(&mm->tlb_flush_pending);
645 * Where the increment if constrained by the PTL unlock, it thus
646 * ensures that the increment is visible if the PTE modification is
647 * visible. After all, if there is no PTE modification, nobody cares
648 * about TLB flushes either.
650 * This very much relies on users (mm_tlb_flush_pending() and
651 * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and
652 * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc
653 * locks (PPC) the unlock of one doesn't order against the lock of
656 * The decrement is ordered by the flush_tlb_range(), such that
657 * mm_tlb_flush_pending() will not return false unless all flushes have
662 static inline void dec_tlb_flush_pending(struct mm_struct
*mm
)
665 * See inc_tlb_flush_pending().
667 * This cannot be smp_mb__before_atomic() because smp_mb() simply does
668 * not order against TLB invalidate completion, which is what we need.
670 * Therefore we must rely on tlb_flush_*() to guarantee order.
672 atomic_dec(&mm
->tlb_flush_pending
);
675 static inline bool mm_tlb_flush_pending(struct mm_struct
*mm
)
678 * Must be called after having acquired the PTL; orders against that
679 * PTLs release and therefore ensures that if we observe the modified
680 * PTE we must also observe the increment from inc_tlb_flush_pending().
682 * That is, it only guarantees to return true if there is a flush
683 * pending for _this_ PTL.
685 return atomic_read(&mm
->tlb_flush_pending
);
688 static inline bool mm_tlb_flush_nested(struct mm_struct
*mm
)
691 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL
692 * for which there is a TLB flush pending in order to guarantee
693 * we've seen both that PTE modification and the increment.
695 * (no requirement on actually still holding the PTL, that is irrelevant)
697 return atomic_read(&mm
->tlb_flush_pending
) > 1;
703 * typedef vm_fault_t - Return type for page fault handlers.
705 * Page fault handlers return a bitmask of %VM_FAULT values.
707 typedef __bitwise
unsigned int vm_fault_t
;
710 * enum vm_fault_reason - Page fault handlers return a bitmask of
711 * these values to tell the core VM what happened when handling the
712 * fault. Used to decide whether a process gets delivered SIGBUS or
713 * just gets major/minor fault counters bumped up.
715 * @VM_FAULT_OOM: Out Of Memory
716 * @VM_FAULT_SIGBUS: Bad access
717 * @VM_FAULT_MAJOR: Page read from storage
718 * @VM_FAULT_WRITE: Special case for get_user_pages
719 * @VM_FAULT_HWPOISON: Hit poisoned small page
720 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded
722 * @VM_FAULT_SIGSEGV: segmentation fault
723 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page
724 * @VM_FAULT_LOCKED: ->fault locked the returned page
725 * @VM_FAULT_RETRY: ->fault blocked, must retry
726 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small
727 * @VM_FAULT_DONE_COW: ->fault has fully handled COW
728 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs
729 * fsync() to complete (for synchronous page faults
731 * @VM_FAULT_HINDEX_MASK: mask HINDEX value
734 enum vm_fault_reason
{
735 VM_FAULT_OOM
= (__force vm_fault_t
)0x000001,
736 VM_FAULT_SIGBUS
= (__force vm_fault_t
)0x000002,
737 VM_FAULT_MAJOR
= (__force vm_fault_t
)0x000004,
738 VM_FAULT_WRITE
= (__force vm_fault_t
)0x000008,
739 VM_FAULT_HWPOISON
= (__force vm_fault_t
)0x000010,
740 VM_FAULT_HWPOISON_LARGE
= (__force vm_fault_t
)0x000020,
741 VM_FAULT_SIGSEGV
= (__force vm_fault_t
)0x000040,
742 VM_FAULT_NOPAGE
= (__force vm_fault_t
)0x000100,
743 VM_FAULT_LOCKED
= (__force vm_fault_t
)0x000200,
744 VM_FAULT_RETRY
= (__force vm_fault_t
)0x000400,
745 VM_FAULT_FALLBACK
= (__force vm_fault_t
)0x000800,
746 VM_FAULT_DONE_COW
= (__force vm_fault_t
)0x001000,
747 VM_FAULT_NEEDDSYNC
= (__force vm_fault_t
)0x002000,
748 VM_FAULT_HINDEX_MASK
= (__force vm_fault_t
)0x0f0000,
751 /* Encode hstate index for a hwpoisoned large page */
752 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16))
753 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf)
755 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \
756 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \
757 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK)
759 #define VM_FAULT_RESULT_TRACE \
760 { VM_FAULT_OOM, "OOM" }, \
761 { VM_FAULT_SIGBUS, "SIGBUS" }, \
762 { VM_FAULT_MAJOR, "MAJOR" }, \
763 { VM_FAULT_WRITE, "WRITE" }, \
764 { VM_FAULT_HWPOISON, "HWPOISON" }, \
765 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \
766 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \
767 { VM_FAULT_NOPAGE, "NOPAGE" }, \
768 { VM_FAULT_LOCKED, "LOCKED" }, \
769 { VM_FAULT_RETRY, "RETRY" }, \
770 { VM_FAULT_FALLBACK, "FALLBACK" }, \
771 { VM_FAULT_DONE_COW, "DONE_COW" }, \
772 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
774 struct vm_special_mapping
{
775 const char *name
; /* The name, e.g. "[vdso]". */
778 * If .fault is not provided, this points to a
779 * NULL-terminated array of pages that back the special mapping.
781 * This must not be NULL unless .fault is provided.
786 * If non-NULL, then this is called to resolve page faults
787 * on the special mapping. If used, .pages is not checked.
789 vm_fault_t (*fault
)(const struct vm_special_mapping
*sm
,
790 struct vm_area_struct
*vma
,
791 struct vm_fault
*vmf
);
793 int (*mremap
)(const struct vm_special_mapping
*sm
,
794 struct vm_area_struct
*new_vma
);
797 enum tlb_flush_reason
{
798 TLB_FLUSH_ON_TASK_SWITCH
,
799 TLB_REMOTE_SHOOTDOWN
,
801 TLB_LOCAL_MM_SHOOTDOWN
,
803 NR_TLB_FLUSH_REASONS
,
807 * A swap entry has to fit into a "unsigned long", as the entry is hidden
808 * in the "index" field of the swapper address space.
814 #endif /* _LINUX_MM_TYPES_H */